private void GenerateLookupPermutation(Generator generator, LoadableValue context, LookupCache cache, int index, LoadableCache[] values, LoadableValue source_reference, Block block)
{
if (index >= values.Length)
{
block(context, cache);
generator.DebugPosition(this);
return;
}
var labels = new Label[values[index].Types.Length];
for (var it = 0; it < labels.Length; it++)
{
labels[it] = generator.Builder.DefineLabel();
values[index].Value.Load(generator);
generator.Builder.Emit(OpCodes.Isinst, values[index].Types[it]);
generator.Builder.Emit(OpCodes.Brtrue, labels[it]);
}
generator.EmitTypeError(source_reference, String.Format("Expected type {0} for “{1}”, but got {2}.", String.Join(" or ", from t in values[index].Types select Stringish.NameForType(t)), values[index].NameInfo.Name, "{0}"), values[index].Value);
for (var it = 0; it < labels.Length; it++)
{
generator.Builder.MarkLabel(labels[it]);
var sub_cache = new LookupCache(cache);
sub_cache[values[index].NameInfo] = new AutoUnboxValue(values[index].Value, values[index].Types[it]);
var builder = generator.Builder;
GenerateLookupPermutation(generator, context, sub_cache, index + 1, values, source_reference, block);
generator.Builder = builder;
}
}
internal void GenerateLookupCache(Generator generator, IEnumerable <Tuple <RestrictableType, Generator.ParameterisedBlock <Generator.ParameterisedBlock <LoadableValue> > > > specials, LookupCache current, LoadableValue source_reference, LoadableValue context, LoadableValue self_frame, Block block)
{
generator.DebugPosition(this);
var lookup_results = new List <LoadableCache>();
if (specials != null)
{
var child_context = generator.MakeField("anon_ctxt", typeof(Context));
var child_frame = generator.MakeField("anon_frame", typeof(MutableFrame));
generator.Builder.Emit(OpCodes.Ldarg_0);
generator.LoadTaskMaster();
source_reference.Load(generator);
context.Load(generator);
self_frame.Load(generator);
generator.Builder.Emit(OpCodes.Newobj, typeof(MutableFrame).GetConstructors()[0]);
generator.Builder.Emit(OpCodes.Stfld, child_frame.Field);
generator.Builder.Emit(OpCodes.Ldarg_0);
child_frame.Load(generator.Builder);
context.Load(generator.Builder);
generator.Builder.Emit(OpCodes.Call, typeof(Context).GetMethod("Prepend", new[] { typeof(Frame), typeof(Context) }));
generator.Builder.Emit(OpCodes.Stfld, child_context.Field);
// Promote the context with the specials to proper status
context = child_context;
foreach (var entry in specials)
{
var next = generator.DefineState();
var field = generator.MakeField("special$" + entry.Item1.Name, typeof(object));
// The types that we might allow are a superset of the ones we
// might actually see. So, build a set of the ones we see.
Type known_types = 0;
entry.Item2(result => {
child_frame.Load(generator.Builder);
generator.Builder.Emit(OpCodes.Ldstr, entry.Item1.Name);
generator.LoadReboxed(result, typeof(object));
generator.Builder.Emit(OpCodes.Call, typeof(MutableFrame).GetMethod("Set", new[] { typeof(string), typeof(object) }));
generator.CopyField(result, field);
generator.JumpToState(next);
known_types |= AstTypeableNode.TypeFromClrType(result.BackingType);
});
generator.MarkState(next);
lookup_results.Add(new LoadableCache(field, entry.Item1.RestrictedType & known_types, entry.Item1, entry.Item1.MustUnbox));
}
}
var base_lookup_cache = new LookupCache(current);
var all_children = new List <NameInfo>();
foreach (var info in Children.Values)
{
if (info == null)
{
continue;
}
info.AddAll(all_children);
}
if (current != null)
{
string narrow_error = null;
foreach (var info in all_children)
{
var current_narrow_error = info.CheckValidNarrowing(base_lookup_cache, current);
if (narrow_error != null && current_narrow_error != null)
{
narrow_error = String.Format("{0}\n{1}", narrow_error, current_narrow_error);
}
else
{
narrow_error = narrow_error ?? current_narrow_error;
}
}
if (narrow_error != null)
{
generator.LoadTaskMaster();
source_reference.Load(generator);
generator.Builder.Emit(OpCodes.Ldstr, narrow_error);
generator.Builder.Emit(OpCodes.Callvirt, typeof(TaskMaster).GetMethod("ReportOtherError", new[] { typeof(SourceReference), typeof(string) }));
generator.Builder.Emit(OpCodes.Ldc_I4_0);
generator.Builder.Emit(OpCodes.Ret);
return;
}
}
var load_count = all_children.Sum(info => info.NeedsLoad(current) ? 1 : 0);
if (load_count > 0)
{
generator.StartInterlock(load_count);
lookup_results.AddRange(from info in all_children where info.NeedsLoad(current) select info.Load(generator, source_reference, context));
var state = generator.DefineState();
generator.SetState(state);
generator.DecrementInterlock(generator.Builder);
var end_label = generator.Builder.DefineLabel();
generator.Builder.Emit(OpCodes.Brfalse, end_label);
generator.Builder.Emit(OpCodes.Ldc_I4_0);
generator.Builder.Emit(OpCodes.Ret);
generator.Builder.MarkLabel(end_label);
generator.JumpToState(state);
generator.MarkState(state);
}
foreach (var lookup_result in lookup_results.Where(x => x.DirectCopy))
{
base_lookup_cache[lookup_result.NameInfo] = lookup_result.Value;
}
foreach (var lookup_result in lookup_results.Where(x => x.SinglyTyped && !x.DirectCopy))
{
base_lookup_cache[lookup_result.NameInfo] = new AutoUnboxValue(lookup_result.Value, lookup_result.Types[0]);
var label = generator.Builder.DefineLabel();
lookup_result.Value.Load(generator);
generator.Builder.Emit(OpCodes.Isinst, lookup_result.Types[0]);
generator.Builder.Emit(OpCodes.Brtrue, label);
generator.EmitTypeError(source_reference, String.Format("Expected type {0} for “{1}”, but got {2}.", Stringish.NameForType(lookup_result.Types[0]), lookup_result.NameInfo.Name, "{0}"), lookup_result.Value);
generator.Builder.MarkLabel(label);
}
var permutable_caches = lookup_results.Where(x => !x.SinglyTyped && !x.DirectCopy).ToArray();
var old_paths = generator.Paths;
generator.Paths = permutable_caches.Aggregate(old_paths, (acc, c) => acc * c.Types.Length);
if (generator.Paths > 200 && !combinatorial_explosion)
{
Console.Error.WriteLine("{0}:{1}:{2}-{3}:{4}: There are {5} type-derived flows in the generated code. This will be slow to compile.", FileName, StartRow, StartColumn, EndRow, EndColumn, generator.Paths);
combinatorial_explosion = true;
}
GenerateLookupPermutation(generator, context, base_lookup_cache, 0, permutable_caches, source_reference, block);
generator.Paths = old_paths;
}